package cn.cnsuh.剑指offer.q10_青蛙跳台阶问题;

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int n = sc.nextInt();

        System.out.println(numWays(n));
    }

    static int numWays(int n) {
        int[] dp = new int[110];
        dp[0] = 1;
        dp[1] = 1;
        dp[2] = 2;
        for(int i = 3 ; i <= n ; i++){
            dp[i] = (dp[i-1] + dp[i-2])%1000000007;
        }
        return dp[n];
    }
}
